COPYRIGHT

All files in this project are licensed under the Apache License,
Version 2.0 [1] and MIT license [2], at your option.

   Copyright 2020 Richard R. Masters and Contributors

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use any file in this project except in compliance with
   the License. You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

Under the definitions of the Apache 2.0 license:
Unless You explicitly state otherwise, any Contribution intentionally
submitted for inclusion in the Work by You to the Licensor shall be under the
terms and conditions of the Licenses above, without any additional terms
or conditions. (Per the second sentence of Section 5 of the Apache 2.0 license,
this term for contributions is not superseded by the first sentence of
Section 5 of the Apache 2.0 license.)

Side Note: This dual licensing strategy is the same as that used by the Rust
project, the Racket project, and many others [3]

[1] See file LICENSE-APACHE (original at https://www.apache.org/licenses/LICENSE-2.0)
[2] See file LICENSE-MIT (original at https://opensource.org/licenses/MIT)
[3] https://internals.rust-lang.org/t/rationale-of-apache-dual-licensing/8952
    https://blog.racket-lang.org/2019/11/completing-racket-s-relicensing-effort.html